Thursday, May 18, 2017

Stripes Aren’t Only On Zebras, You May Find Them On Chicken Breasts Too

Stripes Aren’t Only On Zebras, You May Find Them On Chicken Breasts Too
by Jocelyn Ngo

Have you ever noticed thin white stripes between the fibers on your chicken breasts? Have you ever occasionally noticed a chicken breast that is a little tougher or firmer to chew? If so, you have stumbled upon chicken breasts coming from chicken with two different types of muscle disorders.

Since chicken breasts have increased in popularity, surpassing beef in 2010, due to the movement to healthier diets, there has been an increase in demand for chicken breast over beef and pork, Muscular diseases called White striping and Woody breasts have recently become a larger concern to consumers, secondary chicken manufacturers, and chicken growers. White striations laced between muscle fibers in chicken breasts and unappealing yellowish color with firmness upon compression occur in birds that are bred to grow at a rapid rate to feed the growing population and demand for lean meat. For consumers, this chicken muscle disorder affects texture and nutritional content of the chicken breasts. For secondary chicken manufacturers, these myopathies negatively affect the processing yields and finished product quality. For chicken growers, successfully mass producing large chickens from the traditional 70 days at 3.08lbs to 47 days at 6.24lbs to keep up with demands is negatively affecting quality of the raw commodity.

Woody breast and White striping usually occur within the same breast. While white striping affects the appearance and nutritional content of the chicken breast, woody breast mainly affects texture. Woody breast can be detected when one compresses force down upon the breast and experience a hard, “woody”, texture. Frequently, woody breast will show a ridge on the surface of the descending end,  a yellowish tint, and a viscous clear fluid on the chicken.

White Striping in chickens is a recent concern, with oldest studies dating back to  only 2009. Simply put, White striping has occurred mainly in chickens that have higher growth rates. Because of the increasingly high demand for this lean meat due to nutritional factors such as higher protein or price, farmers have chosen to grow breeds with high growth weight and breast yields. White striping has been characterized with muscle degeneration. Consumers can mistake this problem as something comparable to meat marbling, like in beef. White striping is however different because chickens do not normally store fat between their muscles like beef do.

Because low quality chicken with white striping and woody breast is being produced at the beginning of the supply chain, all products that the chicken is being used thereafter are negatively affected. For chicken product manufacturers, white striping affects texture and product yield. Stiffness of the muscles and intramuscular striations of fat between the muscles cause decreased water holding capacity and protein functionality. As a result, manufacturers who use marinades in processing to add flavor and/or other functional uses, are resulting in lower meat yields and quality. Lower meat yields, affect the quality of the product as well as profit. For the consumer, some may notice a difference in texture after cooking and the obvious appearance of white striping on a chicken breast. Also, because of white stripping, the chicken breast may not be as nutritionally beneficial since the fat content in the breast may double while also decreasing the protein content.

White striping and Woody breast are negatively affecting the poultry industry by misconceiving consumers, affecting processors meat yields, and deteriorating finished product quality. White striping on chicken breasts occur when striations parallel to the muscle fibers of fat appear on the surface of the breast. Although the National Chicken council claims that this phenomenon only affects a “small percentage of chicken”, a study sampling 285 breasts found that 95% of chicken breast sampled had white striping, causing other researchers to look into this problem. Woody Breast imparts a tough texture and reduction in water holding capacity in chicken breasts. Spreading this knowledge of these phenomenon will help consumers choose the right quality of chicken when purchasing their groceries and for manufacturers be to aware of profit loss for the reduction of yield caused by a decreased water binding capacity.

Wednesday, May 10, 2017

FSNSA Year in Review (2016 - 2017)

FSNSA Year in Review
2016 – 2017

Thank you to all students, alumni, faculty, staff, and special guests that were able to join us at this year's Food Science Awards Night (May 5, 2017). We had an amazing night and awesome turn out! In case you missed it, below are links to...not one, but two different takes on the year in review! Enjoy and see you all next year! Looking forward to seeing what the 2017 – 2018 academic year brings!


Tuesday, May 9, 2017

Aren’t You Glad There’s a New Way to Process Juice? Thermosonication for Fruit and Vegetable Juices

Aren’t You Glad There’s a New Way to Process Juice? 

Thermosonication for Fruit and Vegetable Juices

by Danielle Rosen

            Springtime is here again, and with it comes a new harvest of fresh fruit and vegetables. From juicy apricots to white asparagus, phytonutrient-filled seasonal produce can be found both in gardens and grocery stores, but consumers are looking for new ways to get their daily five.  One trend that has become popular is to get the daily dose of fruits and vegetables in the form of fresh juices, however many juices that are available on the market are not as “fresh,” as consumers believe them to be. Traditional processing methods such as pasteurization for fruits and vegetable juices which often rely on high heat to reduce spoilage bacteria and enzymes to safe-to-consume levels, also degrade the color, taste, and nutrient composition of fruit and veggie juices. Because of the negative effects of traditional fruit and vegetable juice processing, many juice manufactures add preservatives, colorings, and flavors to get a more desirable product. Is a fruit or vegetable juice filled with preservative and reduced vitamin C content what consumers really want? The answer is most likely no, but new methods of processing can produce fresher juices with nutrients and taste that consumers love.

            Thermosonication is a form of minimal processing that works by applying low heat and low frequency sound waves to the fruit and vegetable juices. By combining low heat forms of pasteurization with the novel processing technique of ultrasound, two different spoilage reduction processes are applied to the juice to create a safe to consume product without degrading important nutrients and sensory aspects like color and taste. Thermosonication has been used in many different types of fruit and vegetable juices, and generally applies a frequency of around 20 kilohertz (kHZ) anywhere between 40-80°C for several seconds to 10 minutes. Time, temperature, and frequency combinations change depending on the type of fruit or vegetable juice, the nutrient content, viscosity, and intended purpose (such as straight to the bottle, or used in another product), but all forms rely on low frequency and low temperature to preserve nutrients and sensory attributes like appearance and taste.
To understand thermosonication a little better, let’s look at how it works for processing a consumer favorite, fresh orange juice. First, the oranges are harvested and the juice is extracted. Once the raw orange juice is ready, it is put into a large vat surrounded by a pre-heated water bath of 45°C. An ultrasound probe is then put into the middle of the vat of orange juice, and waves of 20kHZ are administered for several minutes. As the invisible sound waves travel through the vat of juice, they pass through the spoilage bacteria, causing their cell walls to break and thus killing the bacteria. As the waves are destroying the bacteria, the water bath is destroying the spoilage enzymes bacteria that can lead to browning or mold growth in the juice.
Now that you know how thermosonication works, the question is, does it really work? Still looking at orange juice, the key nutrient, vitamin C, is retained at 85-98% whereas orange juice processed with pasteurization only has 85% retention or less. Spoilage enzymes are reduced by 90% or more, and dangerous bacteria like E. Coli and Salmonella are destroyed. Thermosonicated juices also tend have a more appealing appearance, flavor, and texture than juices treated with high heat alone. These benefits of thermosonication are amazing, because they are achieved without the addition of ANY preservatives, added vitamins, or colorings, and it results in a cleaner ingredient list, fresher product, and happier consumer.